1. Field of the Invention
The present invention relates to an imaging apparatus including a photographic lens protection unit.
2. Description of the Related Art
For imaging apparatuses such as digital video cameras, digital cameras and the like, lens cap type protection units are used for protecting the photographic lens. Conventional lens cap type protection units attach a lens cap having an attachment structure to a filter screw thread on the object side of a front lens element of the photographic lens. Since the lens cap is detached when capturing an image, it has been proposed to link the lens cap to the grip belt of the imaging apparatus by a cord or the like to prevent the lens cap from being lost (Japanese Patent Application Laid-Open No. 11-271839).
Further, a structure has been commercially developed which provides a cover for the lens cap protection unit, a so-called “lens barrier”, that when an image is not being captured is positioned on the object side of a front lens element of the photographic lens to protect the photographic lens, and when an image is being captured retracts from the object side of a front lens element of the photographic lens. As the lens barrier, there are a type where the user of the imaging apparatus moves the cover manually, and a type where the cover is moved electrically using a motor.
Lens barrier covers are typically one of two types: a rotating type which opens and shuts by rotating a plurality of blade members like a diaphragm; or a sliding type which operates by making about one or two plate-shaped members slide across. For sliding type lens barriers, two types are representative: barriers which are exposed to the front face of the device body and which form an exterior part (see Japanese Patent Application Laid-Open No. 2004-173100); and lens barriers built into the body which are arranged inside the exterior part of the device body and are only exposed to the outside at the photographic lens opening (see U.S. Patent Application Publication No. 2005/0094027). Since the latter type does not need to take up a large surface area on the exterior of the device front face, in recent years this type is used in many digital video cameras and digital still cameras.
However, for a lens barrier which is built into the body, when capturing an image, a plate-shaped member has to be stored in the body. Specifically, a space for housing the plate-shaped member of the lens barrier has to be provided inside the imaging apparatus. Further, the plate-shaped member of the lens barrier needs to be arranged on the object side of the front lens element of the photographic lens.
For an imaging apparatus, there are many elements which need to be arranged on the object side, such as a flash unit, a microphone, a remote control light receiving element, and the like. Conventionally, the flash unit and the microphone have been arranged at a position which avoids the operating range of the plate-shaped member of the lens barrier. For example, in the ultra-small video camera discussed in U.S. Patent Application Publication No. 2005/0094027, the microphone is arranged on the upper face of the device to avoid the lens barrier built into the body and to avoid the front face which is used for holding the device by hand. With this structure, the microphone faces out from the upper face rather than from the object side, and thus this structure has the drawback that sound from the object side cannot be efficiently collected. Arranging the microphone on the face of the object side while avoiding the lens barrier built into the body inevitably leads to an increase in the surface area of the object side of the imaging apparatus body.
FIG. 8 illustrates an external perspective view of a video camera mounted with a conventional lens barrier built into the camera body. FIGS. 9A and 9B illustrate a frontal view and a mid-section cross sectional view of a state where the lens is protected by a lens barrier. FIGS. 10A and 10B illustrate a frontal view and a mid-section cross sectional view of a lens exposed state.
On a conventional video camera 110, the lens barrier 112 can be made to slide up and down by manually moving the barrier knob 114 up and down. The lens barrier 112 protects the photographic lens 124 when an image is not being captured, and exposes the photographic lens 124 to the object side when an image is captured. When the photographic lens 124 is exposed to the object side, the lens barrier 112 is retracted into the lens barrier retraction space 120 illustrated in FIG. 9B.
The microphone 122 for collecting the sounds of an object is arranged on a lower side of the lens barrier retraction space 120. The front face of the video camera 110, specifically, the external surface area when viewed from the object face side, needs to be equal to or greater than the sum of the surface area of the lens barrier 112, the surface area of the lens barrier retraction space 120, and the surface area of the microphone 122.
Further, like in this conventional example, when the microphone 122 is arranged on a lower side of the lens barrier retraction space 120, the height 118 of the video camera lens barrel portion increases.
If a medium that is quite large, such as a magnetic tape or an optical disk, is used as the recording medium of the recording unit 116, the height of the lens barrel portion is not often viewed as a problem.
However, in recent years, smaller recording media, such as hard disks or memory cards, have become more popular as the recording medium used in video cameras. This trend towards smaller recording media means that the object side surface area of the device body, specifically, the device itself, can be made smaller. From the aspects of both portability and exterior design, it is becoming necessary to house the lens barrier so that the object side surface area of the imaging apparatus becomes smaller.